1. Field of the Invention
The present invention relates to a semiconductor device for large power, such as IGBT module. Also, the invention is applied to the structure of semiconductor device required to reduce the power loss.
2. Description of the Related Art
A structure, as shown in FIG. 9 for instance, is known as an example of semiconductor device for large power according to the prior art. Here, this example relates to the structure of IGBT module.
In FIG. 9A, a collector side of an IGBT chip 65 and an n layer side of a diode chip 66 are soldered respectively, on a Cu pattern 63 of the surface of a DBC (Direct Bond Copper) substrate wherein copper conductors sandwich an insulation substrate 67 of alumina. An emitter side of the IGBT chip 65 and a p layer side of the diode chip 66 are connected with an external power terminal 61, through an Al bonding wire of, for example, 200 to 500 μmφ, extending from both chips. On the other hand, the surface Cu pattern 63 is connected to an external power terminal 62. Such structure is placed on a heat radiation plate 69. In FIG. 9A, a gate terminal 70 shown in FIG. 9B is not illustrated.
On the other hand, in a conventional module structure as shown in FIG. 9A, the external power terminal 61 is connected with the chip 65, 66 through the bonding wire 64. Consequently, wiring resistance caused by the bonding wire 64 and self-inductance increase inconveniently.
Therefore, the present invention is devised considering problems of the aforementioned structure, and has an object of providing a semiconductor device for large power, such as IGBT module, reducing a wiring resistance caused by the wiring metal such as bonding wire, and self-inductance, and further improving the heat diffusion.